• Title/Summary/Keyword: 정중 신경

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Real-Time Decoding of Multi-Channel Peripheral Nerve Activity (다채널 말초 신경신호의 실시간 디코딩)

  • Jee, In-Hyeog;Lee, Yun-Jung;Chu, Jun-Uk
    • Journal of IKEEE
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    • v.24 no.4
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    • pp.1039-1049
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    • 2020
  • Neural decoding is important to recognize the user's intention for controlling a neuro-prosthetic hand. This paper proposes a real-time decoding method for multi-channel peripheral neural activity. Peripheral nerve signals were measured from the median and radial nerves, and motion artifacts were removed based on locally fitted polynomials. Action potentials were then classified using a k-means algorithm. The firing rate of action potentials was extracted as a feature vector and its dimensionality was reduced by a self-organizing feature map. Finally, a multi-layer perceptron was used to classify hand motions. In monkey experiments, all processes were completed within a real-time constrain, and the hand motions were recognized with a high success rate.

Study of Computed Tomography Reconstruction Angle of Bony Stenosis of the Cervical Foramen (경추 신경공 골성 협착에서 CT 재구성 각도 연구)

  • Yon-Min, Kim
    • Journal of the Korean Society of Radiology
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    • v.16 no.7
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    • pp.919-925
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    • 2022
  • This study is an image reconstruction method after cervical CT scan. According to the oblique coronal reconstruction angle, i would like to suggest the reconstruction angle that can best express neural foraminal bony stricture. The angle created by drawing a line passing through the center of the spinal cord in the midsagittal plane of the cervical spine and the uncovertebral joint was measured. A line passing through the center of the spinal cord was drawn from the neural foramen, and the angle formed with the midsagittal plane was measured and compared. At the C4-5 level, the average was 9.2°, at the C5-6 level, the average was 9.9°, and at the C6-7 level, the average was 8.4°, the neural foraminal angle was measured to be larger than the uncovertebral joint angle. There was a statistically significant difference in mean (p<0.01). Also, it was found that the angle increased toward the lower cervical vertebrae. The angle between the neural foramen of the lower cervical vertebrae (C5-6, C6-7) and the center of the spinal cord is between 55 and 60°. Here, if the oblique coronal image is reconstructed to be 90°, the degree of neural foramen stenosis can be observed well. Because it is an image reconstruction using a conventional CT scan image, it does not receive additional radiation exposure. It is of great significance in diagnosing cervical neural foramen bony stenosis.

AOA Estimation Algorithm Using Interconnected Neural Network Model (상호결합형 신경망 모델을 이용한 실시간 도래방향 추정알고리즘에 관한 연구)

  • 정중식;임정빈;안영섭
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2003.05a
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    • pp.111-114
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    • 2003
  • It has well known that MUSIC and ESPRIT algorithms estimate angle of arrival(AOA) with high resolution by eigenvalue decomposition of the covariance matrix which were obtained from the array antennas. In the case that 2-D large-sized array antenna is required, however, one of the disadvantages of MUSIC and ESPRIT is that they are computationally ineffective, and then they are difficult to implement in real time. To alleviate the computational complexity, several method using neural model have been study. For multiple signals, those methods require huge training data prior to AOA estimation. This paper proposes the algorithm for AOA estimation by interconnected hopfield neural model. Computer simulations show the validity of the proposed algorithm.

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Trilateral Retinoblastoma - Case Report - (일측성 망막아세포종과 동반된 이소성 정중선 원시신경외배엽종 - 증례보고 -)

  • Kim, Hyung Seok;Cho, Kyung Gi;Cho, Ki Hong;Yoon, Soo Han;Ahn, Young Min;Ahn, Young Hwan;Shim, Chul
    • Journal of Korean Neurosurgical Society
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    • v.30 no.5
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    • pp.647-651
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    • 2001
  • Trilateral retinoblastoma is a syndrome involving midline intracranial malignancies in children with the heritable form of retinoblastoma. It is rare and usually lethal in spite of aggressive treatments. We report a case of trilateral retinoblastoma with review of the literature to gain further insight into this uncommon disease.

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Shape, Volume Prediction Modeling and Identical Weights Cutting for Frozen Fishes (동결생선의 외형과 부피 예측 모델링 및 정중량 절단)

  • Hyun, Soo-Hwan;Lee, Sung-Choon;Kim, Kyung-Hwan;Seo, Ki-Sung
    • Journal of the Korean Institute of Intelligent Systems
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    • v.22 no.3
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    • pp.294-299
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    • 2012
  • This paper suggests a modeling technique for shape and volume prediction of fishes to cut them with identical weights for group meals. The measurement and prediction of frozen fishes for group meals are very difficult because they have a bending deformation occurring at frozen stage and a hollow by eliminating the internals. Besides there exist twinkles problem of surface caused by freeze and variable weights by moisture conditions. Therefore a complex estimation algorithm is necessary to predict the shape and volume prediction of fishes exactly. Hollow prediction, pattern classification and modeling for tails using neural network, integration based volume prediction algorithm are suggested and combined to solve those problems. In order to validate the proposed method, the experiments of 3-dimensional measurement, volume prediction and fish cutting for spanish mackerel, saury, and mackerel are executed. The cutting experiments for real fish are executed.

Two Cases of Pneumatic Tourniquet Paralysis: Points for Prevention (공기주입 구혈대로 인한 상지마비 2예: 예방을 위한 수칙)

  • Kim, Hyonsurk;Kim, Young Ho
    • Archives of Hand and Microsurgery
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    • v.23 no.4
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    • pp.313-318
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    • 2018
  • Although nerve injury is the most common complication of pneumatic tourniquets, it is said to be rare, with few case reports. We describe two cases of paralysis after upper extremity surgery to highlight this risk. Ulnar, median and radial neuropathies were diagnosed after surgery was performed on a man for left hand reconstruction, presumably due to a prolonged total inflation time of 14 hours despite conventional break times. A woman who received surgery for a crushed hand presented with radial neuropathy, the most probable cause being malfunction and automatic inflation of the tourniquet. These cases illustrate the diversity of tourniquet paralysis, with symptomatic progress not necessarily following electromyography results. The considerable discomfort to patients warrants careful use of tourniquets for neuropathy prevention.

Prediction of Long-term Runoff for Hapcheon Dam Watershed through Multi-Artificial Neural Network Downscaling of KMA's RCM (기상청 RCM전망의 다지점 인공신경망 상세화를 통한 합천댐 유역의 장기유출 전망)

  • Kang, Boo-Sik;Moon, Su-Jin;Kim, Jung-Joong
    • Proceedings of the Korea Water Resources Association Conference
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    • 2012.05a
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    • pp.948-948
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    • 2012
  • 합천댐유역에 대한 기후변화에 따른 수문학적 영향을 정량적으로 분석하기 위해, 기상청에서 제공하는 공간해상도 27km의 MM5 RCM(Regional Climate Model)을 사용하였다. RCM의 기상변수들은 공간적 스케일의 상이성과 RCM 기후변수들의 불확실성 때문에 유출모형인 SWAT의 입력자료로 사용하기에는 어려움이 있다. 특히, RCM 변수들 중 강수량의 경우 한반도 지역의 6월과 10월 사이에 연강수량의 67%이상이 집중되는 계절성을 반영하지 못하고 있는 실정이기 때문에 국내 유역의 유출량 산정에 사용하기 위해서는 지역적 상세화(Downscaling)가 필요하다. 본 연구에서는 RCM 기후변수에 내포된 공간적 스케일의 상이성과 불확실성을 최소화하기 위해 강우관측소 지점을 단위로 한 다지점 인공신경망 기법을 적용하여 강수량, 습도, 최고기온 및 최저기온에 대한 상세화를 실시하였다. 강수의 경우 여름철 태풍사상을 모의하기 위한 Stochastic Typhoon Simulation기법과 Baseline(1991~2010)과 Projection(2011~2100) 사이의 강수량 보정을 위한 Dynamic Quantile Mapping 기법을 적용하여, 강수량의 불확실성을 최소화 하고자 하였다. 상세화된 기후자료를 이용한 SWAT 모형의 일(Daily) 단위 강우-유출 모의결과를 2011~2040년, 2041~2070년, 2071~2100년으로 구분하여 추세분석을 실시하였다.

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Real Time AOA Estimation Using Neural Network combined with Array Antennas (어레이 안테나와 결합된 신경망모델에 의한 실시간 도래방향 추정 알고리즘에 관한 연구)

  • 정중식;임정빈;안영섭
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2003.05a
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    • pp.87-91
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    • 2003
  • It has well known that MUSIC and ESPRIT algorithms estimate angle of arrival(AOA) with high resolution by eigenvalue decomposition of the covariance matrix which were obtained from the array antennas. However, the disadvantage of MUSIC and ESPRIT is that they are computationally ineffective, and then they are difficult to implement in real time. The other problem of MUSIC and ESRPIT is to require calibrated antennas with uniform features, and are sensitive to the manufacturing facult and other physical uncertainties. To overcome these disadvantages, several method using neural model have been study. For multiple signals, those require huge training data prior to AOA estimation. This paper proposes the algorithm for AOA estimation by interconnected hopfield neural model. Computer simulations show the validity of the proposed algorithm. The proposed method does not require huge training procedure and only assigns interconnected coefficients to the neural network prior to AOA estimation.

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Real Time AOA Estimation Using Analog Neural Network Model (아날로그 신경망 모델을 이용한 실시간 도래방향 추정 알고리즘의 개발)

  • Jeong, Jung-Sik
    • Journal of Navigation and Port Research
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    • v.27 no.4
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    • pp.465-469
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    • 2003
  • It has well known that MUSIC and ESPRIT algorithms estimate angle of arrival(AOA) with high resolution by eigenvalue decomposition of the covariance matrix which were obtained from the array antennas, However, the disadvantage of MUSIC and ESPRIT is that they are computationally ineffective, and then they are difficult to implement in real time. the other problem of MUSIC and ESPRIT is to require calibrated antennas with uniform features, and are sensitive ti the manufacturing fault and other physical uncertainties. To overcome these disadvantages, several method using neural model have been study. For multiple signals, those methods require huge training data prior to AOA estimation. This paper proposes the algorithm for AOA estimation by interconnected Hopfield neural model. Computer simulations show the validity of the proposed algorithm. It follows that the proposed method yields better AOA estimates than MUSIC. Moreover, out method does not require huge training procedure and only assigns interconnected coefficients to the neural network prior to AOA estimation.

Miniscrew Installation Area and Condition on Maxillary Palatal Side (상악구개측 미니스크류 식립위치 및 조건)

  • Lee, Ki-Yeon;Lee, Jin-Woo
    • Journal of Dental Rehabilitation and Applied Science
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    • v.25 no.1
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    • pp.61-71
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    • 2009
  • Anchorage control is important in orthodontic treatment. Recently miniscrew is widly used as maximum anchorage in orthodontic treatment, and then it is important to install miniscrew safely without damaging adjacent anatomic structure. In a view of Miniscrew's stability, maxilla is unfavorable than mandible, and moreover maxillary soft buccal bone has disadvantage on stability. so palatal area comes into notice for installation area. We measured distance between palatal roots and bone thickness at midpalatal area using 3D computed tomography, and have found following results. 1. On the comparison of distance between palatal roots, the distance between 2nd premolar and 1st molar was significantly longest and the distance between premolars was significantly shortest. 2. Going toward lateral area from midpalatal suture and posterior area from zero point, bone thickness significantly became shorter and shorter. And 5.0mm palatal sagittal plane has more significance decrease of bone thickness than 2.5mm palatal sagittal plane. According to these results, we can conclude that the palatal installation of miniscrew between 2nd premolar and 1st molar is safest. And it is more safe that comes closer to midpalatal suture and to anterior area in regard to incisive canal.